cariflex/tools/EVerest-main/lib/everest/framework/everestrs/everestrs

Rust support for EVerest

This is Rust support using cxx.rs to wrap the framework C++ library.

Trying it out

• Install Rust as outlined on https://rustup.rs/, which should just be this one line: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
• Built your workspace as outlined in EVerest README, make sure to tell cMake to enable EVEREST_ENABLE_RS_SUPPORT.
• You can now try building the code, but it will not do anything: cd everestrs && cargo build --all
• You should now be able to configure the RsExample or RsExampleUser modules in your config YAML.

Differences to other EVerest language wrappers

• The enable_external_mqtt is ignored for Rust modules. If you want to interact with MQTT externally, just pull an external mqtt module (for example the really excellent rumqttc) crate into your module and use it directly. This is a conscious decision to future proof, should EVerest at some point move to something different than MQTT as transport layer and for cleaner abstraction.

Status

Full support for requiring and providing interfaces is implemented, missing currently is:

• Support for EVerest logging
• Support for implementations with max_connections != 1 or min_connections != 1

Mocking in Unit-Tests

The Rust wrapper supports mocking, which allows you to unit tests your modules. To enable mocking in your code you need to do some steps however

• Add mockall and mockall_double to your module as dependencies
• Add a mockall feature to your module and enable it for your tests.

Then all publishers are mocked with mockall.

Building from external repositories without CMake

Note that the EVerest (and everest-framework prior to migration to a monorepo layout) repositories are automatically configured for this use case, this section is only relevant for Rust modules residing in their own repositories.

While external Rust modules can be compiled using CMake without any setup, compiling with cargo directly requires some additional setup. This is required for rust-analyzer's IDE integration to work properly.

• First, build your EVerest workspace with Rust support enabled by passing -DEVEREST_ENABLE_RS_SUPPORT=ON to CMake.

• Create a file at modules/.cargo/config.toml in your repository. It file should contain the following, with <build-dir> replaced by the name of your EVerest build directory.

  [env.EVEREST_RS_LINK_DEPENDENCIES]
  value = "../<build-dir>/everestrs-link-dependencies.txt"
  relative = true